Binding element



M. D. LEVITAN BINDING ELEMENT May 31, 1966 3 Sheets-Sheet 1 Filed Sept. 16, 1965 I I NVFNTOR. zzz zcefl. Zeqacaz ATTORNEYS y 1966 M. D. LEVITAN 3,253,603

BINDING ELEMENT Filed Sept. 16, 1963 3 Sheets-Sheet 2 IIIIIIIIH: I/1 7455 SZllI/l/YI/ May 31, 1966 M. D. LEVITAN BINDING ELEMENT 5 Sheets-Sheet 5 Filed Sept. 16, 1963 E IN VENTOR. jfa'zzz a'cefl Leu iczzz wayw A )RNEYS United States Patent 3,253,603 BINDING ELEMENT Maurice D. Levitan, Wilmette, 11L, assignor to General Binding Corporation, Northbrook, Ill., a corporation of Illinois Filed Sept. 16, 1963, Ser. No. 309,075 4 Claims. (Cl. 129-24) The present invention relates to binding elements and is, more particularly, concerned with the provision of an improved loose-leaf binding element manufactured from plastic materials while retaining operational characteristics heretofore existing only in the conventional metal snap-ring binders. As those skilled in the art of looseleaf binders are aware, many relatively flexible types of curled plastic binders have been manufactured and sold. However, such plastic binders have depended upon a resiliency of the plastic fingers to permit removal or inser tion of sheets from the binder. The present invention provides an improved plastic loose-leaf binder of the snap type which does not depend upon flexibility of the sheetretaining fingers for its operation and which, accordingly, provides a far more rigid, durable, and readily operable loose-leaf binding.

Snap action binders of the type previously constructed of metal preferably comprise relatively rigid sheet-retaining fingers secured to backbone plates of rigid steel or other similar metal. These plates are mounted in a spring toggle construction permitting their over-center snap action into either the ring-open or ring-closed position.-

In accordance with the present invention, ring, holding, fingers are constructed integrally with plastic backbone plates that are flexibly secured together along their adjacent edges. Over-center spring force is provided by a separate C-shaped backbone member or, alternatively, may be provided by a portion of plastic material molded integrally with the two plates. Similarly, finger positioning means, in the way of actuators and stop abutments are integrally mounted into the plates providing substantially unitary plastic binding mechanism capable of mass production manufacture from high tensile strength plastic material such as polypropylene or high density polyethylene which are readily molded into complex forms and have very high resistance to flexure fatigue failure in thin cross-section.

It is, accordingly, an object of the present invention to provide a relatively inexpensive and substantially improved loose-leaf binder element for use with punched sheets.

Another object of the present invention is to provide a substantially rigid plastic binder of a snap action type.

Still a further object of the invention is to provide a plastic snap-action loose-leaf binder having an integral backbone, actuating mechanism, spring mechanism, and sheet retaining fingers.

A feature of the invention resides in providing a pair of backbone plates carrying fingers rigid therewith, arranged with a flexible connection between the plates.

Another feature of the invention, in a modified form, comprises provision of an extruded plastic backbonespring member operable to provide snap action in combination with plastic finger-carrying plates.

Another feature of the invention resides'in the provision of a combined backbone element for securement of notebook covers simultaneously constructed to provide spring action for a pair of snap-action loose-leaf finger plates.

Still a further object of the invention is to provide a loose-leaf binderelement having staggered, overlapping, substantially rigid fingers.

3,253,603 Patented May 31, 1966 ice Still other and further objects and features of the invention will become at once apparent to those skilled in 'the art from a consideration of the attached drawings wherein several embodiments of the invention are illustrated by way of example only, and wherein:

FIGURE 1 is a plan view of a plastic binding element constructed in accordance with the principles of the present invention;

FIGURE 2 is an end elevational view of the binder as shown in FIGURE 1, slightly enlarged;

FIGURE 3 is an end elevational view of the binder shown in FIGURES 1 and 2 with the parts shown in the binder-closed condition;

FIGURE 4 is an end elevational view of the binder element employed in FIGURES 1 through 3 in the asmolded position;

FIGURE 5 is an end elevational view of the binder illustrated in FIGURES 2 and 3 and illustrating the respective positions of punched sheets and sheet lifters in co-operation therewith;

FIGURE 6 is a plan view of a modified form of the present invention;

FIGURE 7 is a cross-sectional view taken along the line VIIVII of FIGURE 6;

FIGURE 8 is a cross-sectional view in the same plane as FIGURE 7 showing the parts in their binder-open condition;

FIGURE 9 is an end-elevational view of the binder shown in FIGURES 7 and 8 in the as-molded condition;

FIGURE 10 is a diagrammatic illustration of a modified form of the combined backbone and spring member adapted for use with the embodiment of the invention illustrated in FIGURE 1; and

FIGURE 11 is a diagrammatic illustration of still a further modified form of the present invention.

As shown on the drawings As may be seen from a consideration of FIGURES operation with binding covers 11 and 12. As there shown,

the binding element comprises a pair of relatively rigid toggle plates 13 ad 14 carrying respective finger members 15 and 16. The toggle plates are integrally joined to each other along the inboard edges by way of a thin integrally molded hinge 17. Additionally, the toggle plates 13 and 14 carry integrally molded trigger and stop members 18 and 19 respectively. The toggle plates 13 and 14 are biased toward each other by means of a backbone spring member generally in the shape of a C, indicated at 20. In the embodiment illustrated, this backbone comprises plastic which is extruded in the form of the cross-section generally illustrated in FIGURE 3. As there seen, the base of the C configuration is provided with a slot 21 formed for accommodating a sliding indicia bearing label strip 22. Pressure edges 23 form segmental cylindrical bearing edges for co-operation with the mating segmental cylindrical groove surfaces 13:: and 14a. The outboard edges of the backbone are formed with grooves 24 for acommodating the binder covers 11 and 12. The grooves 24 may be extruded in the form shown or as illustrated in the dotted lines at 24a with a subsequent upward curling deformation into tight confining position against the portions 25 which preferably have a slightly beaded edge 25b at the base thereof for the trigger members 18 and 19 be substantially rigid. However, the hinge 17 must have sufiicient flexibility to permit the toggle action to occur while at the same time withstanding the pressure stresses of the toggle action imposed by the spring characteristics of the backbone 20, without fatigue failure. These characteristics are admirably provided by several recently developed plasticmaterials of high tensile strength and great resistance to fatigue failure under flexing conditions. These include, for example, polypropylene, linear or high density polyethylene, and relatively stiff forms of polyallomers which are readily molded and produce stable final molded forms.

In molding the integral toggle plate, finger and trigger element, the element is formed in the position shown in FIGURE 4.- In assembly into the backbone member 20 bearing grooves 13a, 14a are readily moved apart into contact with the respective bearing edges 23 and 24. This is acomplished by moving the trigger elements 18 and 19 toward each other by their outermost ears 18a, 19a. Slightly before the co-operatin-g stops 18b and 19b engage each other, a snug fit is provided bewteen the grooves 13a, 14a and the respective bearing edges 23. Continued movement of the trigger causes an outward expansion of the backbone 20, against resilient force inherent in the backbone, until the stops 18b and 19b, which are provided with beveled surfaces 180 and 190, spring past each other into a retained, assembled condition as illustrated in FIG- URE 2. In this condition, the fingers 13 and 14 are opened for receiving loose leaf sheets and the binder fingers and toggle plates are positively retained in assembled condition relative to the backbone by the stops 18b, 19b. In this position additional projections 23a on backbone prevent the binding from pinching the covers 11, 12. If desired, springing the triggers 18, 19 past each other again position the binder unit for disassembly from the backbone.

The binding element is movable into its closed condition by further movement of the triggers 18 and 19 in the direction of the arrows shown in FIGURE 2, until the toggle plates 13 and 14 snap over center into the position shown in FIGURE 3. In this position triggers 18 rest against stops 19d and plates 13 and 14 preferably rest against the backbone 20.

The control of the loose-leaf sheets in the binder is illustrated in FIGURE 5. As there shown, a sheet-lifter is shown in dotted lines in various positions beginning at the relatively fiat condition illustrated at 25a to the relatively vertical position 25b assumed when the binder covers are closed. It will be observed that the curved junction between the fingers '15 and 16 and their respective toggle plates 13 and 14, as indicated at 13b and 14b, provides a cam surface deflecting the innermost edge 26 of the individual sheet lifter 25 inwardly toward the hinge 17 when the covers 11 and 12 are opened into the position shown in FIGURE 5. Accordingly, the loose-leaf sheets 10 move naturally, from their weight, from their initial position generally indicated at 10a into the fiat, open position without jamming. This smooth, angled, relationship between the fingers and toggle plates not only provides the above mentioned camming action but also permits a particularly strong, rigid, toggle plate and finger combination capable of transferring the relatively heavy spring forces from the backbone 20 to the hinge connection 17. Similarly, the configuration illustrated provides improved sheet lifting action when the binder covers are lifted into the closed position, such as shown in FIGURE 3. This is true since pressure from the binder cover 12 against the lifter 2 first mum at the outer edge of the lifter 25 with a resultant movement of the lifter 25 upwardly from the position shown in 250 to 25b. During this movement, the edge 27 slides up the inner surface of the backbone while the edge 28 of the opening slides up the outer surface of the rings as illustrated in the position 25a. The length of the individual sheet lifter perforations 29 is proportionate relative to the sides 4 of the backbone fingers, as illustrated in FIGURE 5 to permit dual contact between the lifter and the fingers and with a resultant camming action readily controlling the position of the sheets in the binder during opening and closing, Without jamming.

In the embodiment of the invention illustrated at FIG- URES 6, 7, 8, and 9, the basic one-piece, integral hinge construction illustrated in FIGURES 1 through 3 is continued. However, in place of the separate backbone 20 illustrated in the embodiment of FIGURES 1 through 5, an integral spring is molded directly into the finger toggle plate unit. This may clearly be seen from a consideration of FIGURES 7 and 8. As there shown, a spring portion 30 is molded into integral hinged relationship with toggle plates 130' and 140. The unstressed condition of the spring portion 30 is illustrated in FIG- URE 9 where the as-molded condition of the unit is illustrated. As the fingers 150 and 160 are forced toward each other, the spring portion 30 is stressed into the form shown in FIGURE 8. When the fingers are moved still further in the direction of closure, into the position shown in FIGURE 7, the toggle plates 130 and 140 snap over center and their return to the open position is permitted by stress in the spring portion 30.

It will be observed relative to the embodiment shown in FIGURES 6 through 9 that the extruded type of backbone illustrated at 20 in the embodiment of FIGURES 1 through 5 is not required. Instead, the backbone unit may be assembled to any form of backing member by means of a rivet, or as illustrated, a screw 31 threaded into a nut portion 32 in the backing member 33. Operation of the fingers may readily be accomplished in such installation merely by pushing the fingers together or pulling them apart manually, or, alternatively, by providing integrally molded trigger members similar to those illustrated in FIGURES 2 and 3. As a further alternative, a combined trigger and locking element, as indicated at 35 in FIGURES 6, 7 and 8 may be employed.

In operation, the trigger element 35 piv-otally oscillates about the bolt 31. In the closed condition of the binder element, as illustrated in FIGURES 6 and 7, knobs 36 abut, against the under edges a and a at positions outwardly of the connection between the spring portion 30 and the toggle plates 130 and 140. This positioning forces the outboard end of the toggle plates up, as viewed in FIGURE 7, for example, and the inboard hinge portion downwardly against the plate 35. When the trigger element35 is oscillated by movement of the handle 38 toward the right, as viewed in FIGURE 6, the upwardly projecting buttons 36 move inwardly of the hinge connections between the spring portion 30 and their respective toggle plates. This movement acts against the under surface of the toggle plates to move the inboard ends upwardly away from the backing member as viewed in FIGURE 8, causing the toggle plates to snap over center into the open position illustrated. In view of the positive abutting position of the buttons 36 in the closed condition as shown in FIGURE 7, opening of the binder element, by forcing open the fingers, is prevented. Similarly, in the position shown in FIGURE 8, the binding is prevented from closing. In order to distribute the stress properly, it is preferred that a trigger member 35 be provided at both ends of the backbone element.

It will be observed that various modifications may be made in the several structures illustrated without departing from the scope of the novel concepts of the present invention. For example, although it is considered de sirable to employ extruded plastic for purposes of the backbone and spring combination element 20, nevertheless the backbone may be constructed of sheet metal. An example of such an arrangement is illustrated in FIGURE 10. There, the backbone 120 comprises spring sheet metal, or the like, bent into a generally C-shaped cross-section. In this structure the innermost edges 123 are substantially identical to the inner edges 23 of the backbone 20 shown in the embodiment of FIGURES 1 through 5, and provide an inwardbiasing force against the toggle plate. In view of the elimination of the binder cover grooves 24, the cover members 111 and 112 may be secured to the backbone 120 by notching the backbone along its length and providing apertures in the covers for co-operation thus formed. As a result of this arrangement the backbone 120 comprises a series of spring elements acting to provide the toggle action, with the individual spring elements simultaneously serving to retain the cover members in assembled relation with the toggle plate-finger unit.

Still a further modification is illustrated in FIGURE 11 where the fingers 250 and 260 are illustrated as interengaging rather than lying in spaced, staggered, relation. In the arrangement shown in FIGURE 11, the fingers 250 and 260 combine to positively retain the individual sheets in the same aperture rather than successive apertures. As a result of this arrangement, the tensile strength of the plastic material utilized in the binder may be somewhat lower without causing excessive flexibility. In allotherrespec-ts, embodiment illustrated in FIGURE 11 is the same as the embodiment form illustrated in FIGURES 7 through 9. It will, of course, be clear that this finger construction may also be employed in the embodiment illustrated in FIGURES 1 through 5.

As pointed out above, various of the modern plastics may be employed in the construction of the present invention. Those particularly suitable include the polyolefins, such as polypropylene and polyethylene. These plastics have high tensile strength and high stiffness while still exhibiting excellent resistance to fatigue failure under fiexure of small sections. Combinations of these materials are also found satisfactory, as are related commercial products such as polyallomers, which have relatively improved resistance to'brittleness at low temperatures. These materials all exhibit a particularly good resistance to flexing failure and, in fact, it has been found that integral hinge sections formed in these materials actually have resistance to failure above resistance of the adjacent thicker sections to such failure. This is particularly true when the hinge portion is flexed initially almost immediately after forming, at which time the molecules of plastic orient themselves across the thin section in a manner providing a particularly strong, yet flexibie, integral hinge.

It will, of course, be apparent to those skilled in the art that further variations and modifications may be made in the structures illustrated without departingfromthe novel concepts of the present invention. It is, accordingly, my intention that the scope of the present invention be limited solely by that of the hereinafter appended claims.

I claim as my invention:

1. In combination in a loose-leaf binder, a toggle action finger unit comprising a pair of toggle plates integrally joined along one edge by a relatively thin flexible portion and each having a plurality of substantially rigid sheet-retaining fingers upwardly curved from the other edge, and spring means comprising at least one strip, joined to said toggle plates, extending upwardly therefrom and between said fingers and acting against said toggle plates biasing them toward their line of joinder to provide a toggle action, said plates, fingers, and spring means being integrally constructed of one-piece high tensile strength plastic.

2. In combination in a loose-leaf binder, a toggle action finger unit comprising a pair of toggle plates integrally jointed along one edge by a relatively thin flexible portion and each having a plurality of substantially rigid sheet-retaining fingers upwardly curved from the other edge, and spring means comprising at least one strip, joined to said toggle plates, extending upwardly therefrom and between said fingers and acting against said toggle plates biasing them toward their line of joinder to provide a toggle action, said plates, fingers, and spring means being integrally constructed of polypropylene plastic.

3. A loose-leaf binder construction in accordance with claim 1 including trigger means operative against said toggle plates for biasing said toggle plates back and forth from a finger-open to a finger-closed condition.

4. The loose-leaf binder construction in accordance with claim 2 including trigger means operative against said toggle plates for biasing said toggle plates back and forth from a finger-open to a finger-closed condition.

References Cited by the Examiner UNITED STATES PATENTS 974,831 11/ 1910 Scherzinger 129-24 2,439,675 4/ 1948 Segal 129-24 2,612,169 9/ 1952 Segal 129-24 3,105,494 10/ 1963 Duncan 129-24 3,111,949 11/1963 Duncan et a1. 129-24 3,132,649 5/ 1964 Gits 129-24 FOREIGN PATENTS 1,319,334 1/1963 France.

WALTER A. SCHEEL, Primary Examiner.

WENCESLAO J. CONTRERAS, Assistant Examiner. 

1. IN COMBINATION IN A LOOSE-LEAF BINDER, A TOGGLE ACTION FINGER UNIT COMPRISING A PAIR OF TOGGLE PLATES INTEGRALLY JOINED ALONG ONE EDGE BY A RELATIVELY THIN FLEXIBLE PORTION AND EACH HAVING A PLURALITY OF SUBSTANTIALLY RIGID SHEET-RETAINING FINGERS UPWARDLY CURVED FROM THE OTHER EDGE, AND SPRING MEANS COMPRISING AT LEAST ONE STRIP, JOINED TO SAID TOGGLE PLATES, EXTENDING UPWARDLY THEREFROM AND BETWEEN SAID FINGERS AND ACTING AGAINST SAID TOGGLE PLATES BIASING THEM TOWARD THEIR LINE OF JOINDER TO PROVIDE A TOGGLE ACTION, SAID PLATES, FINGERS, AND SPRING MEANS BEING INTEGRALLY CONSTRUCTED OF ONE-PIECE HIGH TENSILE STRENGTH PLASTIC. 